This is the latest attack off the coast of Nigeria, Africa’s largest oil producer.

The captain, chief engineer and second engineer were abducted on Monday when gunmen boarded the Malaysia-flagged Armada Tuah 22 around 50 nautical miles off the coast of the Brass region in the Niger Delta, three security sources said.

One of the sailors kidnapped was Indonesian, the sources said.

The vessel is a tugboat contracted to supply an offshore oil platform.